Maximum security lock bolt

ABSTRACT

A maximum security lock bolt of composite construction which captivates an insert of a material which is substantially impervious to machining operations, such as a ceramic material, the insert being of a size sufficient to span or bridge the gap between the locked door and strike plate mounted on the associated door jamb.

O Unlted States Patent 1151 3,659,885 Nail [451 May 2, 1972 541 MAXIMUM SECURITY LOCK BOLT 2,374,840 5/1945 Schonitzer ..292/2 1,446,589 2/1923 Shaw ..70/417 [72] Inventor. Billie G. Nail, La Crescenta, Cal1f. 1,358,404 1 H1920 wens. 292/2 X [73] Assignee: Adams Rite Manufacturing Company, 608,784 8/1898 Mix ...,.292/2 Gl d l C lif, 863,584 8/1907 Blechschmidt ..292/2 [22] Filed: Aug. 31, 1970 FOREIGN PATENTS OR APPLICATIONS [21] App1.No.: 68,314 690,247 4/1953 Great Britain ..70/417 Primary ExaminerRobert L. Wolfe [52] U.S.Cl ..292/2,70/41l A I &M 51 1111.01 ..E05b 15/16 tomey c [58] Field Of Search ....292/2, DIG. 38, DIG. 56; 57 ABSTRACT A maximum security lock bolt of composite construction I 56] References Cited which eaptivates an insert of a material which is substantially 1mperv1ous to machmmg operatlons, such as a ceram1c maten- UNITED STATES PATENTS al, the insert being of a size sufficient to span or bridge the gap I between the locked door and strike plate mounted on the asl,786,221 12/1930 Ph1ll1ps ..70/417 Sociated doorjamh 761,843 6/1904 Lyan 70/417 X 1,599,459 9/ 1 926 Colombi ..292/2 9 Claims, 7 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to the field of locks.

For a great many years, lock manufacturers have been attempting to provide a maximum of security in locks for general use in stores, home, and the like. A great deal of the research in this area has been in connection with attempts to build a lock bolt which would successfully resist the known methods and procedures as utilized by persons intent upon making an unlawful entry.

In this connection various types of constructions have been used in an effort to develop a bolt which could be economically produced and yet afiord an exceedingly high degree of security. Laminated bolts using case hardened metals, tough hard steel materials, and the like, have been used, but these materials could be cut with saws of tungsten carbide materials or certain tough steels.

The present invention proposes to overcome this problem by utilizing a captivated insert of a ceramic material commercially known as AD 94 Ceramic, which is available from Coors Porcelain Co. of Golden, Colorado, or an equivalent material. These materials have an extremely high degree of hardness and are substantially impossible to machine or cut with a tungsten carbide or steel saw. By captivating this insert, which might become fractured, it would still be able to effectively perform its function.

SUMMARY OF THE INVENTION The present invention relates generally to locks, and is more particularly concerned with the structure embodied in the lock bolt in order to obtain a maximum of security.

Having in mind the inherent disadvantages of the prior attempts to successfully solve this problem. It is an object of the present invention to provide an improved lock bolt which can be produced economically, and yet which will provide a greater degree of protection than possible in heretofore known structures.

Another object is to provide a lock bolt of composite construction, which utilizes as one of the materials in its construction, a ceramic material having extreme hardness and which is substantially impervious to machining or cutting operations.

Another object of the herein described invention is to provide a bolt construction having a ceramic insert captivated therein so that in the event that the insert should become fractured, it will still operate efficiently as a deterrent to attempts to cut through the bolt structure.

A still further object is to provide a ceramic insert of such configuration that it may be readily adapted without change for use in both short and long bolt structures.

Further objects and advantages of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing several embodiments of the invention without placing limitations thereon.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the accompanying drawings, which are for illustrative purposes only:

FIG. 1 is a perspective view of a locking mechanism having a bolt embodying the present invention, together with an associated door jamb having a bolt receiving opening therein;

FIG. 2 is a detailed elevational view of a bolt as shown in FIG. 1, portions being cut away to disclose the captivated insert therein;

FIG. 3 is a transverse section through the bolt taken substantially on line 3-3;

FIG. 4 is a longitudinal section taken substantially on line 4- of FIG. 2;

FIG. 5 is a fragmentary view disclosing a modified ceramic insert configuration for use in long bolts;

FIG. 6 is a similar view utilizing the same insert but shifted in its orientation to adapt it for use in short bolt structures; and

FIG. 7 is a fragmentary view illustrating the insert as used in a hook-type bolt.

DESCRIPTION OF THE SEVERAL DISCLOSED EMBODIMENTS Referring more specifically to the drawings, for illustrative purposes, the present invention is shown as being embodied in a lock structure which is secured in one face of a door frame 10, the lock structure being provided with a conventional face plate 11 retained by screws 12 and having an opening 13 through which a locking bolt 14 is actuatable by conventional key actuated lock cylinder means 15 into extended locking position and retracted unlocked position. In the locked position, the bolt 14 will extend into a bolt receiving opening 16 of an associated door jamb 17.

It will be appreciated that in the locked door position, a gap will necessarily exist between the edge of the locked door and the associated door jamb, which provides a space wherein a cutting tool such as a saw may be inserted for the purpose of attempting to saw through the bolt and thus gain unlawful entry. It is the broad concept of the present invention to circumvent such an operation by providing a lock structure which will contain a material which will span the gap between the locked door and the associated jamb, and which material will be substantially impervious to known cutting methods.

In carrying out this concept, the lock bolt 14 is internally provided with an internal cavity 18, which in this case may be made in one of the bolt laminations, having in this case a square or rectangular configuration, and within which there is seated and captivated a ceramic insert 19. This insert is of such width that it will span the gap between the locked door and the adjacent door jamb. The material of the insert is as previously identified, or its equivalent. It will be appreciated that by captivating the insert in this manner, should it become fractured, it will still efi'ectively perform its function. While it might be possible to penetrate the outer material of the bolt by a sawing operation, the continued penetration will be circumvented efi'ectively by the ceramic insert.

Referring to FIGS. 5 and 6, it will be seen that the insert 19' has been modified as to its configuration so that by orienting the insert as shown in FIG. 5 it can be utilized with a long bolt structure such as that shown in FIG. 2, while by shifting it to a position as shown in FIG. 6 it is usable in the conventional short bolt structure. This dual application is possible by cutting off one of the comers of the rectangular configuration, as indicated at 20.

Referring now to FIG. 7, an insert 19" of smaller dimensions than that utilized in the structures of FIGS. 5 and 6 is shown as being used with a hook-type bolt structure 14'. In this arrangement, it will be observed that the insert is positioned in the material at the bottom of the hook portion of the bolt.

From the foregoing description and drawings, it will be clearly evident that the delineated objects and features of the invention will be accomplished.

Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific forms shown or uses mentioned.

I claim:

1. A maximum security bolt for a door lock adapted in a locked position of the door to bridge the gap between the door and associated door jamb, comprising:

a. a composite bolt structure including:

at least one main body part of a machinable material; and

an element rigidly secured against relative movement on said part and having a dimension, in the locked position of the bolt, at least as great as the gap between the locked door and door jamb, said element being of a non-metallic material having a hardness 2. A maximum security bolt for a door lock adapted in a locked position of the door to bridge the gap between the door and associated door jamb, comprising:

locked position of the door to bridge the gap between the door and associated door jamb, comprising:

a. a composite bolt structure including:

a laminated main body part formed of a plurality of plate members of a machinable material; and a flat plate element positioned in parallel relation between the outermost plate members of said body part having a dimension, in the locked position of the bolt, at least as great as the gap between the locked door and door jamb, said element being of non-metallic material having a hardness substantially greater than that of the material of the main body plates and being substantially impervious to machining operations.

4. A bolt according to claim 2, wherein the element is captivated by the main body part.

5. A bolt according to claim 4, wherein the main part is constructed with an internal cavity, and said element is confined within said cavity.

6. A bolt according to claim 5, wherein the cavity and element have conformed perimeters.

7. A bolt according to claim 6, wherein the element comprises a multi-sided insert.

8. A bolt according to claim 7, wherein the insert is of rectangular configuration.

9. A bolt according to claim 3, wherein the main part has hook-shaped plate members and the element is positioned at the bottom portion of the hook. 

1. A maximum security bolt for a door lock adapted in a locked position of the door to bridge the gap between the door and associated door jamb, comprising: a. a composite bolt structure including: at least one main body part of a machinable material; and an element rigidly secured against relative movement on said part and having a dimension, in the locked position of the bolt, at least as great as the gap between the locked door and door jamb, said element being of a non-metallic material having a hardness
 2. A maximum security bolt for a door lock adapted in a locked position of the door to bridge the gap between the door and associated door jamb, comprising: a. a composite bolt structure including: at least one main body part of a machinable material; and an element of ceramic material carried by said part having a dimension, in the locked position of the bolt, at least as great as the gap between the locked door and door jamb, said element being of material having a hardness substantially greater than that of the material of the main body part and being substantially impervious to machining operations.
 3. A maximum security bolt for a door lock adapted in a locked position of the door to bridge the gap between the door and associated door jamb, comprising: a. a composite bolt structure including: a laminated main body part formed of a plurality of plate members of a machinable material; and a flat plate element positioned in parallel relation between the outermost plate members of said body part having a dimension, in the locked position of the bolt, at least as great as the gap between the locked door and door jamb, said element being of non-metallic material having a hardness substantially greater than that of the material of the main body plates and being substantially impervious to machining operations.
 4. A bolt according to claim 2, wherein the element is captivated by the main body part.
 5. A bolt according to claim 4, wherein the main part is constructed with an internal cavity, and said element is confined within said cavity.
 6. A bolt according to claim 5, wherein the cavity and element have conformed perimeters.
 7. A bolt according to claim 6, wherein the element comprises a multi-sided insert.
 8. A bolt according to claim 7, wherein the insert is of rectangular configuration.
 9. A bolt according to claim 3, wherein the main part has hook-shaped plate members and the element is positioned at the bottom portion of the hook. 